Three Iranians arrested Thursday for illegally entering Pakistan may have been linked to last month's deadly bomb attack in Iran, Pakistani police said.

The three Iranian Baluchis were arrested at the border town of Turbat, around 500 kilometres (310 miles) west of Quetta, in Pakistan's southwestern province of Baluchistan, Raoof Breach, Turbat's police chief, told AFP.

- We suspect they may have some links with the suicide attack in Iran - Breach added, referring to the October 18 attack in which 42 people, including 15 members of Iran's elite Revolutionary Guard, were killed.

The attack took place in the town of Pisheen, in Iran's restive Sistan-Baluchestan province, which borders Pakistan.

Breach said all of those arrested were young.

- They have no documents, and crossed the border some days ago. We are questioning them - he said.

Iran has said those responsible for the October 18 attack were based in Pakistan and has demanded that Islamabad hand over Abdolmalek Rigi, the leader of the Sunni rebel group Jundallah (Soldiers of God).

Islamabad has strongly denied that Jundallah launched the attack from its territory.